1. Field of the Invention
The present invention relates to a liquid crystal display electronic watch and more particularly to a mechanical construction thereof.
2. Description of the Prior Art
Recent rapid development of electronic technique and the like has resulted in real problem in constructing liquid crystal display electronic watches. The liquid crystal display electronic watch is of up-to-date design, but encumbered with a number of difficult problems which impede its practical use as proven by those already proposed and sold in the market, place contrary to the mechanical watch which has a history of several hundred years and subsequently developed hand type electronic watch. The pressing need at present is to provide a liquid crystal display electronic watch which provides a material decrease in electric wirings; takes up less dead space owing to effective arrangement of constitutional elements; provides the least possible members for displaying date and/or week day; and of which the constitutional elements are similar in construction with each other and simple in operation.
The conventional liquid crystal display electronic watch has a number of disadvantages.
As shown in FIG. 25, a circuit construction of the conventional liquid crystal display electronic watch comprises: a crystal oscillator circuit 2; an oscillation frequency divider circuit 6; a time keeping decoder drive circuit 9 composed of a correction circuit, a time keep circuit and decode circuit; and a display circuit 10 receiving signals from the decode circuit and for displaying week day, date, hour, minute, second and the like. The time keeping circuit receives an output signal from the oscillation frequency divider circuit 6 and counts time to deliver an output to the decode circuit. The correction circuit receives an output signal from the oscillation frequency divider circuit 6 and also receives a signal produced when an exteriorly operating member is operated to make a switch member ON or OFF, thereby delivering an output signal to the time keeping circuit and hence operating the decode circuit and the display circuit 10 to correct the display effected by the display circuit.
The correction circuit becomes unstable when the switch member is OFF so that there is a risk of the correction circuit being erroneously operated when the switch member is ON. Thus, the correction circuit must be held in its stable state, during the time when the switch member is OFF state. For this purpose, it has been the common practice to use a system such as that shown in FIG. 7. In the system shown in FIG. 7, those circuit portions of a correction circuit 109 which correspond to the above mentioned switch members are connected through level shifting resistors R.sub.1 to R.sub.5 to a (-) terminal which is grounded. This system, however, has the disadvantage that it takes up much space, is liable to limit the arrangement of the other watch members or electron circuits, and is liable to make the watch thick and large.
There are two kinds of cases, one of which can remove a movement from a back cover side, and the other of which can remove the movement from a dial side. Heretofore, it has been the common practice to use a setting lever to detachably mount a winding stem on the watch in the case of applying one kind of movement to the above mentioned two kinds of cases. But, the use of such setting lever is limited to one of the two kinds of cases only, and as a result, when it is desired to detachably mount the winding stem on the other kind of case, provision must be made of means other than the setting lever.
In an electronic watch or recent liquid crystal display watch which makes use of a battery as its power source, it has been the common practice to deform a part of a train-wheel bridge or of a circuit substrate into a depressed portion with surrounds the outer periphery of the battery and into which the depressed portion encloses the battery, so as to determine the position of the battery in its flat surface direction, and to support the battery. A battery supporting member is channel-shape in section.
Such means of supporting the battery by a single substrate of the liquid crystal display electronic watch could not rigidly support the battery in its plane direction, regardless irrespective of shocks subjected to the watch.
In the liquid crystal display electronic watch, a crystal oscillator unit is enclosed in the case with two terminals exteriorly exposed and supported at a given position on a print sheet or watch substrate. Heretofore, it has been the common practice to mechanically support the oscillator unit by the watch substrate and the like by means of a plate-shaped member for pushing the oscillator unit into a socket or by means of solder which is used to directly bond the exterior connection terminals with the print sheet. Electrical connection between the exterior connection terminals and exterior circuits is effected through a socket secured to the watch substrate and the like or is effected by soldering the exterior connection terminals with lead wires. Such conventional crystal oscillator unit, supporting construction, is troublesome and consumes a lot of time to secure the oscillator unit to the plate-shaped member and makes the watch substrate and the like complex in construction.
In the case of a crystal watch and the like which requires a particularly super miniature crystal oscillator, it is impossible to provide a space in which the socket is located. In addition, there is a risk of the crystal oscillator being broken by being subjected to shocks, and, as a result, the crystal oscillator must easily be replaced by a new one.
Heretofore, it has been the common practice to use a transistor and an inductance coil for the purpose of obtaining a booster source. As a result, it is impossible to provide an integrated circuit which corresponds to the above mentioned complementary type MOS integrated circuit. In addition, it is required to use the inductance coil in the form of a coil wound around an iron core. Moreover, the inductance coil can not be made smaller than a given required size in view of its efficiency and requires complex manufacturing steps which causes a hindrance in constructing the watch. In addition, the use of the inductance coil requires a direct current source having an undesirable load changing rate, thereby requiring a circuit for stabilizing the direct current source and hence a number of electron elements. This provides a material increase in volume occupied by the electron elements, which is a vital disadvantage in the case of constructing the watch.
In addition, the liquid crystal display electronic watch, that is, a digital type electronic watch is composed of a LSI such as a C-MOS, or the like, which is complex in circuit construction and has a number of connection points which are required to turn a display member on and off. Particularly, if a liquid crystal cell is used as the display member, it is necessary to replace the liquid crystal cell by a new one since liquid crystal substance has a comparatively short life span. In this case, electrical and mechanical connections are effected with the aid of spring contacts and, as a result, it is difficult to ascertain whether or not the electrical and mechanical connections are reliably completed.
In the digital electronic watch which can effect its display with the aid of a liquid crystal or photodiode, the display is corrected by means of a plurality of push buttons or a crown as in the case of the mechanical watch. In the case of correcting the display by means of a plurality of push buttons, the push buttons are arranged at those positions on the case at which the display is to be corrected, or the positions at which the display is to be corrected are marked on the case for the purpose of preventing erroneous correcting operations, thereby simplifying the operations. But, if the display must be effected with respect, not only to hour and minute but also, to date and week day, it is difficult to provide push buttons for all of the correcting elements of the watch which has limited space. Consequently large numbers of the push buttons makes the design of the watch difficult.
A device for correcting the display by a combination of push buttons so that the number of push buttons can be reduced has also been proposed. Such a device, however, is complex in operation and liable to result erroneous operation.
In the case of correcting the display by means of the winding crown, all of the correcting functions are concentrated at one point and, as a result, such a correcting device is complex in mechanism. Since most of the digital electronic watches make use of a crystal as its standard signal source, these watches have an accuracy with several seconds per month during more than a year's operation. As a result, after these watches have been set, the correction of seconds only is required. Thus, the same operating member, i.e. the crown must be used for the purpose of correcting not only the displays which frequently occur, but also the displays which seldom occur. Such device is also complex in operation and liable to result in erroneous operation.
In chronographs or calendar timepieces, it has heretofore been the common practice to use a correcting push button. In this case, the push button is arranged near the crown, that is, arranged at that portion of the dial which is near two or four o'clock location.
As described above, if the push button is arranged near the winding crown, a setting lever, a clutch lever, gear wheels and the like operated by the winding crown as well as levers operated by the push button are concentrically arranged. Such arrangement makes the mechanism complex in design and manufacture and makes the watch relatively thick. In addition, the watch case is difficult to design.
Thus, it is necessary to separate the push button from the winding crown, and to take into consideration ease of handling and pleasing appearance of the watch.
In the conventional watch, the push button is arranged near the winding crown. The push button arranged near the two o'clock position results in easy handling, but the push button arranged near four o'clock is difficult in handling because, when the watch is put on a user's left wrist, the user must turn his right hand thumb around the winding crown.